GC和HPLC分析金银花多糖的单糖组成方法比较

目的:GC法和HPLC法分析金银花多糖的单糖组成,并对两种方法进行比较。方法:金银花多糖经2.0 mol·L-1的三氟乙酸水解后,用糖腈乙酸酯衍生化-GC法和1-苯基-3-甲基-5-吡唑啉酮(PMP)柱前衍生化-HPLC法分别测定其单糖组成及其比例。结果:GC法检测出金银花多糖由鼠李糖(L-Rha)、阿拉伯糖(D-Ara)、甘露糖(D-Man)、木糖(D-Xyl)、葡萄糖(D-Glc)、半乳糖(D-Gal)组成;HPLC法检测到金银花多糖中含有甘露糖(D-Man)、鼠李糖(L-Rha)、葡萄糖醛酸(D-GlcA)、葡萄糖(D-Glc)、半乳糖(D-Gal)、阿拉伯糖(D-Ara)和木糖(D-Xyl),其中半乳糖(D-Gal)与阿拉伯糖(D-Ara)的色谱峰重叠。结论:两种方法均能检测出中性糖,HPLC法不仅能测中性糖,还能检测出葡萄糖醛酸,对金银花多糖的单糖组成分析GC与HPLC联合使用较为合适。     

Fucoidans as Potential Therapeutics for Age-Related Macular Degeneration—Current Evidence from In Vitro Research

Age-related macular degeneration (AMD) is the major reason for blindness in the industrialized world with limited treatment options. Important pathogenic pathways in AMD include oxidative stress and vascular endothelial growth factor (VEGF) secretion. Due to their bioactivities, fucoidans have recently been suggested as potential therapeutics. This review gives an overview of the recent developments in this field. Recent studies have characterized several fucoidans from different species, with different molecular characteristics and different extraction methods, in regard to their ability to reduce oxidative stress and inhibit VEGF in AMD-relevant in vitro systems. As shown in these studies, fucoidans exhibit a species dependency in their bioactivity. Additionally, molecular properties such as molecular weight and fucose content are important issues. Fucoidans from Saccharina latissima and Laminaria hyperborea were identified as the most promising candidates for further development. Further research is warranted to establish fucoidans as potential therapeutics for AMD.     

日本寒冷地带北海道优良食味粳稻育种研究（网络首发、推荐阅读）

长久以来，北海道产大米的食味口碑一直不高，也未出现像“越光”一样全日本知名的优良食味品种，因此，自1980年开始历时28年，北海道立（现称道总研）农业试验场致力于粳稻优良食味品种快速研究项目的实施。为实现快速研发的目标，通过世代促进栽培法和花药培养法成功缩短了育种年限；采用扩大育种规模的方式，并利用优良食味、耐寒性等内外部有效基因培育兼具优良食味及早熟耐寒性的品种；初期世代开始主要通过分析大米的蛋白质含量、尤其是直链淀粉含量，中间世代则通过少量蒸饭的方式进行食味品鉴，选育出优良食味种系。在食味遗传基因的改良方面，先是集聚北海道优良食味的遗传基因培育出品种“雪光”，再经由北海道品种引进“越光”的优良食味遗传基因，之后以日本东北优良食味遗传基因品种“秋田小町”作为直接杂交母本，分别成功培育出品种“闪光397”和“星之梦”，其直链淀粉含量与以往多肥多产品种的22%相比降低了2%。在此基础之上，引进美国品种“国宝玫瑰”优良食味遗传基因的品种“七星”成功问世，其直链淀粉含量又降低了1%；以变异低直链淀粉种系“北海287号”为母本，成功培育出“梦美”，其直链淀粉含量15%~16%，粘度和软度俱佳，食味亦可与“越光”媲美。     

Chemical composition,antibacterial and antioxidant activity of the essential oils of Metaplexis japonica and their antibacterial components

The aim of this research was to determine the chemical composition, antioxidant and antibacterial properties of the essential oils from Metaplexis japonica and isolation of antibacterial constituents from the essential oils. Results showed that 63 components were identified in essential oils. Phenylethyl alcohol (77.978%), α‐terpineol (31.810%) and docosane (21.644%) were the most abundent constituents of flower oil, leaf oil and fruit oil, respectively. Based on bioactivity‐guided fractionation, three active constituents were isolated and identified as phenylethyl alcohol, α‐terpineol and β‐linalool. Both flower oil and phenylethyl alcohol showed high antibacterial performance, with inhibition zone from 25 ± 0.5 to 11 ± 0.6 mm at highest concentration, and MIC values ranging from 0.125 to 2%. In both DPPH and ABTS assay, the oils showed moderate antioxidant activity. These results indicate potential efficacy of active constituents and essential oils of M. japonica to control food‐borne pathogenic and spoilage bacteria.     

槐米色素和高粱红色素对桑蚕丝织物的拼色研究

为丰富槐米色素和高粱红色素的染色色系,解决其染色色调偏少和配色困难的问题,对这2种染料在桑蚕丝织物上进行不同浓度配比的拼色研究。探讨了直接染色和媒染染色对染色性能的影响,测试了桑蚕丝织物的K/S值及染色牢度。结果表明:槐米色素和高粱红色素具有良好的拼色性能,染色桑蚕丝织物的色光、色深值随着染料浓度配比的变化呈现规律性变化,染色效果较好,可获得多种颜色。媒染染色进一步丰富了色泽,提高了桑蚕丝织物的染色深度和色牢度,各项色牢度均达到3级以上。     

The alginate fermentation strain Pantoea sp. F16-PCAi-T3P21 and ethanol production

Bio-ethanol production from algae is a promising way to help solve the energy problem. Alginate is a major component of algae, but it cannot be utilized by existing ethanol fermentation microorganisms. In order to improve the utilization rate of brown algae, high alginate fermentation strains should be obtained. In this research, strains for algae fermentation were got from several experiments. The ethanol yield of strain A was the highest, which was 0.095 g/g (ethanol to alginate). The identification of strain A was carried out and it was 99% identical to Pantoea sp. F16-PCAi-T3P21. Fermentation experiments with different substrates were carried out, such as laminaran, mannitol, L. japonica and acid hydrolysate of L. japonica, and the ethanol yield rate of L. japonica acid hydrolysate was the highest, which reached 0.17 g/g ethanol to L. japonica. It showed that strain A can converse alginate to ethanol in a relatively high yield rate, and might be a promising strain with L. japonica as the substrate, we believe more research should be carried out on this strain.     

Associations between Oil Yield and Profile of Fatty Acids,Sterols, Squalene,Carotenoids, and Tocopherols in Seed Oil of Selected Japanese Quince Genotypes during Fruit Development

Tocopherols, phytosterols, carotenoids, and squalene are present in mature seeds of Japanese quince. Yet, little is known about the relationship between these compounds and oil yield during fruit and seed development. The profile change of lipophilic compounds during fruit and seed development in Japanese quince cultivars “Darius,” “Rondo,” and “Rasa” is investigated. It is shown here that during fruit and seed development, there is a significant reduction, three‐ to over tenfold, in the concentration of minor bioactive compounds in seed oil. It is recorded that delay between synthesis of tocopherols and oil in Japanese quince seeds during the fruit development results in a logarithmic relationship between the oil content and tocopherols concentration in the seed oil (R² = 0.980). Similar trends are observed between oil yield and phytosterols, and carotenoids (R² = 0.927 and R² = 0.959, respectively). The profile of fatty acids during the development of the seeds significantly is changed. The reduction of linoleic, palmitic, and gondoic acids levels and increment of oleic acid is noted. The oil content, profile of fatty acids, and concentration of bioactive compounds in all three genotypes of Japanese quince do not change significantly statistically during the last month of fruit development. Practical Applications: Some fruits are harvested at different degrees of maturity mainly due to a logistic issue and uneven ripening of fruits, which affects the chemical composition of whole fruit including seeds. Therefore, it would be good to know how the chemical composition is changing in plant material during development especially in the last month before harvest. Production of Japanese quince continues to rise year to year and with it the volume of generated by‐products such as seeds. This study demonstrates how it changes the oil content, profile of fatty acid, and concentration of tocopherols, squalene, phytosterols, and carotenoids in the seeds and seed oil of three Japanese quince cultivars “Rondo,” “Darius,” and “Rasa” during plant development. The provided information can be very useful for the manufactories oriented on the processing of by‐products, mainly seeds, generated by other branches of industry, for instance, fruit‐processing.     

Pyrolysis and co-pyrolysis of Laminaria japonica and polypropylene over mesoporous Al-SBA-15 catalyst

The catalytic co-pyrolysis of a seaweed biomass, Laminaria japonica, and a typical polymer material, polypropylene, was studied for the first time. A mesoporous material Al-SBA-15 was used as a catalyst. Pyrolysis experiments were conducted using a fixed-bed reactor and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). BET surface area, N₂ adsorption-desorption isotherms, and NH₃ temperature programmed desorption were measured to examine the catalyst characteristics. When only L. japonica was pyrolyzed, catalytic reforming slightly increased the gas yield and decreased the oil yield. The H₂O content in bio-oil was increased by catalytic reforming from 42.03 to 50.32 wt% due to the dehydration reaction occurring on the acid sites inside the large pores of Al-SBA-15. Acids, oxygenates, mono-aromatics, poly aromatic hydrocarbons, and phenolics were the main components of the bio-oil obtained from the pyrolysis of L. japonica. Upon catalytic reforming over Al-SBA-15, the main oxygenate species 1,4-anhydro-d-galactitol and 1,5-anhydro-d-manitol were completely removed. When L. japonica was co-pyrolyzed with polypropylene, the H₂O content in bio-oil was decreased dramatically (8.93 wt% in the case of catalytic co-pyrolysis), contributing to the improvement of the oil quality. A huge increase in the content of gasoline-range and diesel-range hydrocarbons in bio-oil was the most remarkable change that resulted from the co-pyrolysis with polypropylene, suggesting its potential as a transport fuel. The content of mono-aromatics with high economic value was also increased significantly by catalytic co-pyrolysis.     

Preparation and Intestinal Immunostimulating Activity of Low Molecular Weight Alginate from Saccharina (Laminaria) Species in Japan

We studied the structure of alginates extracted from five commercial Saccharina (Laminaria) species including three varieties (eight samples in all) harvested in Hokkaido, Japan. The algae used were Saccharina japonica, S. japonica var. diabolica, S. japonica var. ochotensis, S. japonica var. religiosa, S. longissima, S. coriacea, S. angustata, and S. sculpera (Kjellmaniella crassiforia). These alginates have molar fractions of mannuronic acid (F_M) ranging from 0.68 to 0.76 and weight average molecular weights (M_ws) ranging from 511,000 to 616,000. Alginate samples from both S. angustata (F_M = 0.76) and S. longissima (F_M = 0.68) showed intestinal immunological activity through Peyer’s patch cells of C3H/HeJ mice. Low molecular weight S. angustata alginate (F_M = 0.75, M_w = 70,000) degraded using a wet pulverizing system showed higher activity than the native one.